As a construction machine having a cab according to the present invention, there are a motor grader, a bulldozer and the like. In the following description, the motor grader will be described as an example of the construction machine. Generally, the motor grader is a civil engineering machine having wheels for readjusting a land such that a road surface or the ground becomes flat. A blade which readjusts a land can move in the vertical direction, incline in the vertical direction, incline in the longitudinal direction of the vehicle, slide in the left and right direction of the vehicle, and turn around a predetermined pivot.
In order to precisely and efficiently apply a finishing works to a road surface or the ground using the motor grader, an operator carries out the work while seeing the working state after the work or the state of the working place in front of the operator before the operation is carried out. The operator corrects the set angle of the blade while visually checking whether the readjusted state after the work using the blade is formed flatly.
Generally, the motor grader is made to run at high speed on a general road in many cases. Therefore, in the motor grader, it is necessary to secure the visibility on a road surface to be readjusted behind the blade at the time of the readjusting work of the land, and the forward view at the time of running.
A motor grader having a front window largely widened is used in many cases so as to secure the forward view. To check a land-readjusting state after the work, a motor grader having a structure capable of securing forward and downward view by extending the side window glass to a floor area is widely employed. Patent Document 1 (Japanese Patent Laid-Open Publication No. 11-158922), Patent Document 2 (Japanese Patent Laid-Open Publication No. 10-167125) and Patent Document 3 (U.S. Design Pat. No. D531,647) discloses examples of the cab for the motor grader having such a structure.
Patent Document 4 (Japanese Patent Laid-Open Publication No. 5-106240) discloses a cab for a bulldozer having excellent view for both ends of the blade.
Patent Document 1: Japanese Patent Laid-Open Publication No. 11-158922
Patent Document 2: Japanese Patent Laid-Open Publication No. 10-167125
Patent Document 3: U.S. Design Pat. No. D531,647S
Patent Document 4: Japanese Patent Laid-Open Publication No. 5-106240